修复页面间通讯销毁的问题，优化eventor内置事件@linked的发送时机

Tevin

2021-07-09 b925ec64e1bb4e7f0b9ae4242967d67be3a1de9d

 forms/imagePicker/cImagePicker.scss

@@ -20,8 +20,13 @@
            padding: 18px 18px 0 0;
        }
        .at-image-picker__preview-img {
            text-align: center;
            background-color: #f8f8f8;
            position: relative;
            background-color: #f2f2f2;
            img {
                display: block;
                @include position(absolute, 50% 50% n n);
                transform: translate(-50%, -50%);
            }
        }
        .at-image-picker__choose-btn {
            .add-bar {